Power supply apparatuses are essential for many electronic appliances such as personal computers, industrial computers, servers, communication products or network products. Normally, the power supply apparatus may provide stable electricity to the electronic appliance. In a case that the power supply apparatus has a breakdown, the electronic appliance is possibly damaged or the data stored in the electronic appliance is lost. For enhancing capacity and reliability of power supply, a redundant power supply system has been proposed. The redundant power supply system includes a plurality of separated power supply apparatuses, which are electrically to each other and contained in a system cabinet. During operation of the redundant power supply system, individual power supply apparatuses share responsibility for providing electricity to the electronic appliance. If one of the power supply apparatuses has a breakdown and fails to normally provide electricity, the others could continuously provide electricity to the loads.
Referring to FIG. 1, a schematic exploded view of a conventional redundant power supply system is illustrated. The redundant power supply system 1 principally includes a system cabinet 10, a first power supply apparatus 11 and a second power supply apparatus 12. The system cabinet 10 includes a first receptacle 102 and a second receptacle 103, which are separated by a partition plate 101. The first power supply apparatus 11 and the second power supply apparatus 12 are accommodated within the first receptacle 102 and the second receptacle 103, respectively. The redundant power supply system 1 further includes a backside plate 13 inside the system cabinet 10. A first insertion slot 131 and a second insertion slot 132 are disposed on the backside plate 13. A first power connection interface 111 of the first power supply apparatus 11 and a second power connection interface 121 of the second power supply apparatus 12 are respectively inserted into the first insertion slot 131 and the second insertion slot 132 so as to be electrically connected to the backside plate 13. A power cable 14 is extended from the outer surface of the backside plate 13, so that the electricity provided by the redundant power supply system 1 is transmitted to an electronic appliance via the power cable 14.
Referring to FIG. 2, a schematic perspective view of the first power supply apparatus of FIG. 1 is illustrated. The configuration of the second power supply apparatus 12 is substantially identical to that of the first power supply apparatus 11. For clarification and brevity, only the first power supply apparatus 11 is described.
As shown in FIGS. 1 and 2, the first power supply apparatus 11 is swappable to be embedded into the first receptacle 102 of the system cabinet 10. The first power supply apparatus 11 principally includes a casing 110, a connecting part 111, a resilient piece 115, a power socket 117, a handle 118 and a switch element 119. The casing 110 includes a first sidewall 112 and a second sidewall 113, which are adjacent to each other.
The power socket 117, the handle 118 and the switch element 119 are positioned on the first sidewall 112 of the casing 110. The first sidewall 112 and the second sidewall 113 further include a first opening 114 and a second opening 116, respectively. In response to a pulling force exerted on the handle 118, the first power supply apparatus 11 may be withdrawn from the system cabinet 10 of the redundant power supply system 1. In a case that a power plug (not shown) is inserted into the power socket 117, external electricity will be transmitted to the power socket 117 through an external power cable (not shown) and the plug. The switch element 119 is arranged between the resilient piece 115 and the power socket 117 for controlling either conduction or interruption of the external electricity. The resilient piece 115 includes a first end part 115a, a second end part 115b and a protrusion part 115c. The protrusion part 115c is arranged between the first end part 115a and the second end part 115b. The first end part 115a is fixed on the inner surface of the second sidewall 113 of the casing 110. The protrusion part 115c is partially exposed from the second opening 116. The second end part 115b of the resilient piece 115 is exposed from the first opening 114 of the first sidewall 112 of the casing 110. As a consequence, the second end part 115b is served as a suppression part to be pressed by the user.
Please refer to FIGS. 1 and 2 again. When the first power supply apparatus 11 is placed into the system cabinet 10 of the redundant power supply system 1, the protrusion part 115c of the resilient piece 115 is engaged with the recess structure 104 of the system cabinet 10 such that the first power supply apparatus 11 is fixed in the system cabinet 10. For a purpose of withdrawing the first power supply apparatus 11, an external force is exerted on the second end part 115b of the resilient piece 115 (i.e. the suppression part) to have the protrusion part 115c sunken under the second opening 116. Meanwhile, the protrusion part 115c of the resilient piece 115 is disengaged from the recess structure 104 of the system cabinet 10, so that the first power supply apparatus 11 may be pulled out of the system cabinet 10 in response to a pulling force exerted on the handle 118.
The conventional redundant power supply system, however, still has some drawbacks. For example, since the resilient piece 115 is substantially an integral metallic flat plate, the resilient piece 115 is readily subject to distortion after the frequent pressing actions of the resilient piece 115. Especially, the intermediate portion between the first end part 115a and the protrusion part 115c has the highest tendency toward distortion. In a long-term period, the protrusion part 115c of the distorted resilient piece 115 may fail to be effectively engaged with the recess structure 104 of the system cabinet 10, and thus the locking effect is impaired. Moreover, during the power plug is inserted into the power socket 117 to supply the external electricity to the redundant power supply system 1, the protrusion part 115c of the resilient piece 115 may be disengaged from the recess structure 104 of the system cabinet 10 upon carelessly pressing the second end part 115b of the resilient piece 115. Under this circumstance, the first power supply apparatus 11 may be erroneously pulled out of the system cabinet 10.
In views of the above-described disadvantages resulted from the conventional method, the applicant keeps on carving unflaggingly to develop swappable electronic device having a locking element according to the present invention through wholehearted experience and research.